How to Solve: ACT English – Sentence Structure (Run-ons, Fragments, Parallelism, Modifiers)

How to Solve: ACT English – Sentence Structure (Run-ons, Fragments, Parallelism, Modifiers)

Introduction

"Mastering sentence structure on the ACT English section can boost your score by 3–5 points—enough to turn a ‘maybe’ into a ‘yes’ for your dream college. These questions test whether you can spot a run-on, fix a fragment, or keep ideas parallel—skills that also make your essays clearer and more persuasive."

What You Need To Know First

1. Basic sentence parts: Subject, verb, and complete thought.
2. Independent vs. dependent clauses: An independent clause can stand alone; a dependent clause cannot.
3. Punctuation basics: Commas, semicolons, and periods separate ideas.

KEY TERMS & FORMULAS

MEMORIZE THIS: - FANBOYS (coordinating conjunctions): for, and, nor, but, or, yet, so - Subordinating conjunctions: because, although, since, if, when, etc.

Step-by-Step Method

Step 1: Identify the Problem Type

• Run-on? Look for two complete thoughts (independent clauses) smashed together.
• Fragment? Check for missing subject, verb, or complete thought.
• Parallelism? Look for lists or comparisons (e.g., "She likes hiking, swimming, and to bike" → wrong).
• Modifier? Check if the describing word/phrase is next to what it modifies.

Step 2: Apply the Fix

• Run-on: Choose one of the 4 fixes (period, semicolon, comma + FANBOYS, or subordinating conjunction).
• Fragment: Add what’s missing or attach it to a complete sentence.
• Parallelism: Rewrite the list so all items match in structure.
• Modifier: Move the modifier next to the word it describes.

Step 3: Check for Clarity

• Read the sentence aloud. Does it sound smooth? If not, revise again.

Worked Examples

Example 1 – Basic (Run-on)

Question: The dog barked loudly the neighbors complained.

Step 1: Identify the problem. - Two independent clauses: "The dog barked loudly" and "the neighbors complained." - No proper punctuation or conjunction → run-on.

Step 2: Apply the fix. - Option 1: Period → "The dog barked loudly. The neighbors complained." - Option 2: Semicolon → "The dog barked loudly; the neighbors complained." - Option 3: Comma + FANBOYS → "The dog barked loudly, so the neighbors complained."

Step 3: Check for clarity. - All options sound natural. Choose the one that fits the context best.

What we did and why: We spotted two complete thoughts and used proper punctuation/conjunctions to separate them.

Example 2 – Medium (Fragment + Parallelism)

Question: Running down the street, the keys were dropped by Sarah.

Step 1: Identify the problem. - Modifier error: "Running down the street" describes Sarah, but it’s next to "the keys." - Fragment? No—it’s a complete sentence but misplaced.

Step 2: Apply the fix. - Move the modifier next to Sarah: "Running down the street, Sarah dropped the keys."

Bonus Parallelism Check: If the sentence were "Sarah likes running, swimming, and to bike," we’d fix it to "Sarah likes running, swimming, and biking."

What we did and why: We corrected the modifier placement so it describes the right word (Sarah, not the keys).

Example 3 – Exam-Style (Disguised Run-on)

Question: ACT English is tricky it requires practice.

Step 1: Identify the problem. - Two independent clauses: "ACT English is tricky" and "it requires practice." - No punctuation or conjunction → run-on.

Step 2: Apply the fix. - Best option: Comma + FANBOYS → "ACT English is tricky, but it requires practice."

Step 3: Check for clarity. - The sentence now flows logically.

What we did and why: We recognized the run-on and used a comma + conjunction to properly connect the ideas.

Common Mistakes

Exam Traps

1-Minute Recap

"Here’s the night-before cheat sheet for ACT sentence structure: 1. Run-ons? Two complete thoughts need a period, semicolon, or comma + FANBOYS. 2. Fragments? Add a subject, verb, or attach to a complete sentence. 3. Parallelism? Keep lists consistent—nouns with nouns, verbs with verbs. 4. Modifiers? Place them next to the word they describe. 5. Always read aloud—if it sounds wrong, it probably is.

You’ve got this. Now go ace that test!